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Now, before you guys get upset let me state that this thread is about a guy returning to the regular MERV 8 filters.

I have two returns, one is a 16X20X1 and the other is a 20X20X1. For the 16X20 I use a NaturalAire filter (8 Merv) and for the 20X20X1 I was using a 3M Filtrete. Like you all said, the Filtrete loaded up fast so I had to replace it every month (2 months was the longest it would last). I have one more left and noticed something funny on the packaging. It now states (in bold letters with red background) on the cover.

THE INFORMATION ON THIS STICKER SUPERSEDES THE INFORMATION ON THE PACKAGE.

This filter does not outperform all other 1" filters. THIS FILTER IS RATED AT MERV 11 AND ITS MPR IS UNDER 1250. However, it does outperform all fiberglass, non-electrostatic pleated, and washable 1" filters.

1)So, what is the point of MERV? Is it simply a rating of restrictiveness?

2)Does one need anything over a MERV 8?

3)Is there a difference among manufacturers (NaturalAire, American, etc)?

Sorry vettech, I'm in North Carolina. Still looking over the packaging, they now put a sticker that says MERV 11 over the MERV 12 on the packaging. Guess they got a lot of complaints about it being too restrictive or it was not a true MERV 12.

I'm worried about the high pressure drop and wondering what 1" filter I should use.

So Bolton recommends the blue (which I'm told is like having nothing) and vettech recommends getting a paper/polyester filter but change it regularly. See where I get confused?

I think the blue ones are crap myself, but I see the benefit of increased airflow. What paper/polyester filter would you recommend that is as close to a blue in terms of airflow but with better filtering? MERV 1? MERV 2? MERV3?...

so, measure your actual air flow with each filter type & decide -- the general concensis herein is to change to "5" thick filters for the least resistance & the best filtration -- just costs more to go first class --

or, put in carpets & let them catch the dirt -- such as happened to me in 1970 when I put carpet in liv rm & kit -- filter loading dropped 75%!! form 1/wk to 1/mo.